We plan to employ mass spectrometry to study a wide variety of biomedical problems. Particular techniques of mass spectrometry to be stressed include high resolution studies with photoplate detection, use of a field desorption ion source, and coupled gas chromatography-mass spectrometry employing electron impact ionization, chemical ionization and field ionization. Mass spectrometry will be employed in studying problems of structure, biosynthesis, and drug metabolism, with special attention being directed toward antibiotics, alkaloids, compounds of marine origin, and methylphenidate. More than 50 other senior investigators using the Mass Spectrometry Lab will employ mass spectrometry to study nucleosides, enzymes, hormones, terpenes and other problems. A parallel application (for renewal of GM 16,864) is being submitted by Dr. H. S. Gutawsky, Director of the School of Chemical Sciences. The total amount needed is the amount requested in each grant.